1. Field of the Invention
The present invention relates generally to a method and apparatus for detecting disparity.
2. Description of the Prior Art
As 3D television and cinematography is becoming popular, 3D editing effects are being increasingly used.
One 2D effect that is commonly used is multiplexing one image into another, second, image in 2D. An example of this is shown in FIG. 3, where a first image 300 and a second image 305 are to be mixed together. As can be seen in the resultant image 310, the toy bear and house from the first image 300 appear over the mask in the second image 305. In order to achieve this effect, a depth map of each pixel in each image is used to ensure that the positioning of artefacts in the resultant image appear correct. It is important to ensure that when two scenes are edited together, the mixed image appears to have artefacts in the correct physical space. In other words, it is necessary to know which artefact should be placed in the foreground and which should be placed in the background.
A prior art apparatus for achieving this is shown in FIG. 1. In FIG. 1, the first image 300 and the corresponding first depth map 1010 are fed into the mixing apparatus 1000. Additionally, the second image 305 and the second depth map 1020 are also fed into the mixing apparatus 1000. The depth of each pixel is compared from the first and second depth maps 1010 and 1020 in a map comparator 1025. This comparison results in the correct placing of each pixel in the resultant image. In other words, from the depth map it is possible to determine whether the pixel from the first image should be placed behind or in front of a corresponding pixel from the second image.
At each pixel position, the map comparator 1025 instructs a multiplexer 1035 to select for display either the pixel from the first image 300 or the pixel from the second image 305. This generates the mixed image 310. Further, the map comparator 1025 selects the depth corresponding to the selected pixel. This depth value is fed out of the mixing apparatus 1000 and forms the resultant depth map 1045 for the mixed image.
As noted above, as 3D editing is being more frequently required, there is a need to adapt this technique for 3D editing.
It is an aim of the present invention to try and adapt the above mixing technique to the 3D scenario.